Heat regulator device and method



March 13, 1934. -Q J LENS 1,950,499

HEAT REGULATOR DEVICE AND METHOD Filed Feb. 20, 1933 March 13, 1934.

HEAT REGULATOR DEVICE AND METHOD Filed Feb. 20, 1935 3 Sheets-Sheet 2 Mrch 13, 1934. o. J. I ElNs 1,950,499

I HEAT REGULATOR DEVICE AND METHOD Filed Feb. 2o, 195s s sheets-sheet s 9 fQw/ZUR kcafff Zez'ns.

Patented Mar. 13, 1934 PATENT OFFICE HEAT REGULATOR DEVICE AND METHOD Oscar J. Leins, Milwaukee, Wis., assignor to Milwaukee Gas Specialty Company, Milwaukee, Wis., a corporation of Wisconsin Application February 20, 1933, Serial No. 657,635

17 Claims.

This invention relates to a heat regulator device and method.

While the preferred embodiments which I shall describe hereinafter in connection with the drawings are adapted for use with ovens, particularly as embodied in modern domestic ranges, it is to be understood that the invention is not to be limited to this particular use, nor is it to be limited to the details of the particular embodiments illustrated and described.

Heat regulators of the general type to which the preferred embodiments of this invention relate comprise means for controlling the heating medium, that is, the gas, oil, or electric current, and a thermally operated device which actuates the controlling means. Heretofore, it has been customary to mount the thermally operated device within the oven, usually in'such a way and in such a place that it will be exposed G to and indicative of the prevailing temperature within the oven. The controlling device usually has been located away from the oven and, customarily, in proximity to the heating means and its supply.

yAccording to the present invention, instead ci mountingr the thermally operated device within the Nen, as heretofore, I dispose a looped, coiled, or other suitable portion of the fuel or heating medium supply line within the oven to pre-heat the fuel anterior to the burner for the oven. The fuel supply line is provided with a controlling device and the thermally operated device is disposed in the path of th pre-heated supply of fuel posterior to the pre-heating position to be under the direct thermal inuence of the pre-heated fuel and is arranged to vary the position of the control device with variations in the temperature of the pre-heated fuel.

The chief advantage of the present invention lies in freedom from the troubles inherent in thermo-sensitive arrangements exposed inl oven areas where considerable vapor exists and freedom of the thermostatic metal of the thermally operated device from the direct inuence of oven construction variations. Ovens generally are constructed with varying metal thicknesses in their walls, varying ventilation schemes and varying liner arrangements. All of these factors introduce variables in convection, conduction and radiation, which have been uncomfortable problems in oven temperature control endeavors. The present invention provides freedom from these variables.

Another advantage of the present invention lies in the fact that the instrument, as a whole,

may be a unit structure and may be made up very compact and entirely enclosed with respect to delicate mechanisms. The thermally operated device may be mounted in position away or remo-te from the oven as, for example, at and housed directly within the body or housing of the valve which, in the illustrated embodiments of the invention, constitutes the controlling device. Operating connections between a thermally operated device within the oven and a controlling device disposed away or remote from the oven are avoided, and over-shots, undershots, and recoveries are directly related to the temperature of the pre-heated heating mediumy which has a direct and rapid iniluence on the thermostatic metal of the thermally operated device. y

Other advantages and adaptations of the invention will be apparent from the following detailed description of the preferred embodiment of the invention.

In order to acquaint those skilled in the art with the manner of carrying out the method of the present invention and with the manner of constructing and operating a device in a'ccordance with the invention, I shall now describe, in connection with the accompanying drawings, a preferred embodiment of the invention.

In the drawings:

Figure 1 is a perspective view of a gas range showing an embodiment of the present invention in connection therewith;

Figure 2 is a' fragmentary horizontal section through the front panel taken on the line 2-2 of Figure 1, and showing the regulator unit assembly in elevation;

Figure 3 is a vertical section through the regulator unit assembly taken on the line 3-3r of Figure 2;

Figure 4 is .a vertical section similar to Figure 3 through a modified form of regulator unit assembly;

Figures 5, 6, '7 and 8 are fragmentary plan views showing variations in the form of the loop for pre-heating the supply of fuel or heating medium;

Figure 9 is a detail section taken on the line 9-9 of Figure 8; and

Figure l0 is a more or less diagrammatic view of a water heater embodying the present invention.

Referring to the drawings, the gas range designated in its entirety in Figure 1 at 5 is of the cabinet type. It has an oven 6, an underlying broiler compartment 7, and the top burners 8 along the front of which is disposed the panel 9. Compartments 10 and 11 may be provided beneath the top burner portion. The bottom of the range is supported above the floor upon feet 12 and th'e oven 6, broiler compartment 7, and compartments 10 and 11 are provided. with doors 12 which may be hinged along their lower margins and providedat their upper margins,

with handles 13.

The gas supply manfold is indicated at 20 and consists of a forwardly extending portion terminating at its forward end in a manifold part extending along tire/front of the panel 9 rearwardly ofand adjacent the panel 9. Gaseous fuelis led from the front part of the manifold 20 into the respective top burner feed pipes 21 by way of mixing heads 22 through which air is admitted to the outer ends of the feed pipes 21 in the usual manner well known in the art. The inner ends of the feed pipes 21 are connected with and supply the-respective top burners 8, and the nozzle pipes leading from the manifold 20 into the respective mixing heads 22 at the outer ends of the feed pipes 2l are provided with the usual gas cocks 24 positioned `along the front of the panel 9.

An igniter may be provided for the top burners 8 and these burners have the usual overlylng grill for supportingthe cooking vessels in positionl over the respective burners.

Gaseous fuel is also led from the front part of the manifold 20 for the oven'burner 28 by way of a fuel supply pipe 29. The burner 28 is disposed beneath the bottom of the oven 6 as, for example, in the top of the compartment 7, the bottom of which compartment 7 has openings for supplying the air necessary to support combustion at the burner 28 and sufficient to provide the desired air supply to the mixing head 30 which is connected by the feed pipe 31 with the burner 28. The connection 32 from the manifold 20 to the gaseous fuel s'upply pipe 29 is provided with a gas cock 33 positioned at the front of the panel 9 in line with the gas cocks 24 for the top burners.

The gaseous fuel supply pipe 29 extends inwardly from the front part of the manifold 20, and the inner end of the pipe 29 is turned laterally at 29. The outer end of the laterally turned portion 29 is returned or looped back to form a pre-heating loop for the gaseous fuel supply to the burner 28. The loop 35 is preferably made of metal, such as copper or aluminum, of relatively high specific heat properties, and the right hand end (Figure 1) of the return side 39 of the loop 35 is turned forwardly at 40. The forward end of the forwardly extending portion 40 of the oven fuel delivery linel is connected and opens through the inlet 41 into the chamber 42 of the valve body or housing 43 of the controlling device designated in its entirety at 44. The loop 35 extends laterally into the oven compartment and is positioned within the upper part of the oven 6 preferably in such a way and at such a place that it will be subject to the prevailing temperature within the oven. 'I'his loop is subject to the thermal influence of the prevailing oven temperature and serves to preheat anterior to the burner 28 and anterior to the controlling device 44 the gaseous fuel supply from the manifold 20 to the burner 28.

'Ihe fuel supply pipe portion 29 is shown disposed within the top burner space. in which case it is preferably positioned below the plane of the top burners 8 so as not to be thermally influenced by these burners when they are in operation. The forwardly extending fuel supply line portion 40 is also shown disposed within the top burner space and to the right (Figure 1) of the oven wall 36, but it is to be understood that the particular disposition of this fuel supply line portion 40 as Well as the disposition of the connected fuel supply line portion 29 may vary widely within the scope of the present invention. For example, one or both of these fuel supply line portions for the oven burner 28 may be disposed to the left (Figure 1) of the oven wall 36or between the oven wall 36 and the insulating liner 37, or otherwise as desired. In the illustrated embodiment, the loop 35 extends laterally through the adjacent oven wall 36, and where this wall 36 has an inner liner or insulating wall 37 spaced inwardly therefrom and forming an insulating air chamber 38 to prevent too rapid transmission of the heat from the oven through the wall thereof, the loop 35 extends laterally through the liner into the desired position within the oven. Where the extensions 29 i and 40 ofthe fuel feed line are disposed as shown, the oven'wall 36 may have an opening 41 through which the loop 35 passes into the oven 6. The liner 37 is shown as provided with a corresponding opening 41. These openings 4l and 41' are elongated in the direction of the depth of the o-ven for the passage of the loop 35 bodily therethrough and the elongated openings may be closed by a plate or plates 48 suitably secured to the oven wall or liner, or both, over these openings. Instead of the elongated openings 41 and 41', individual openings may be provided for the laterally turned and return portions 29 and 39 of the loop 35 and such individual openings may be provided, if desired, with appropriate closures.

The valve body o-r housing 43 has, in addition to the inlet 4l entering the chamber 42, an outlet 50 leading from this chamber. The fuel supply pipe 51 to the burner 28 is connected at 52 to the outlet 50 and extends rearwardly at 53 and then downwardly at 54 into proximity to the plane of the burner 28. The lower end of the downward extension 54 of this pipe is turned in at 55 into the mixing head 30 for the oven burner, and this mixing head 30 is connected to the oven burner 28 by means of a feed pipe 31. The mixing head 30 is adapted to admit air to the outer end of the feed pipe 31 in the usual tion properly the amount of air with respect to the pre-heated condition of the fuel to providev between the oven wall and the liner, or otherwise l as desired..

'Ihe outlet 50 is controlled by a valve 60 of the disc or mushroom type, and the outer surface of the flange 6l through which the outlet port 50 opens forms a seat at 62 for the annular seating part 63 on the valve 60. The

valve 60 has an outwardly extending central and generally conical enlargement 64 around which -fits the inner end of a generally conical spring 65 and the opposite and larger end of the spring 65 seats ina recess 66 in a removable plug 67 15 which is threaded at 68 into the valve body 43. The reduced end of the conveyor pin 70 passes axially through the valve 60 and its outer end ts and is guided slidingly in an axial recess 71 in the plug 67. Inwardly of the valve 60, the pin 70 is of enlarged diameter at 72 and this enlarged diameter forms a shoulder 73 which abuts the inner side of the valve 60.

The thermally operated device consists of a bi-metallic element 75 disposed Within the chamber 42 to lie directly in the path of the gaseous fuel supply from the supply line 29, 35, 40, through the valve body 43 and on through the supply line 5l, 53, 54, to the burner 28. This element 75 is composed of joined strips 75a and 75l) of diierent metals having different coefficients of expansion as well understood in the art with the strip having the greatest coeicient of expansion positioned on the rear side of the element as viewed in Figure 3. The inner end of the conveyor pin 70 has a reduced projection 76 which extends into an aperture in the adjacent end of the element 75. The bi-metallic element 75 has free abutting contact with the tapered shoulder 77 at the inner end of the enlarged portion 72 of the pin 70, and the opposite side of the bi-metallic element 75 has free abutting contact toward the opposite end ofthe element with a tapered shoulder 78 on the ternperature adjusting or selecting screw 79 of the selecting device designated in its entirety at 30. The inner end of the screw 79 has a reduced projection 8l which extends into an aperture in the element 75 and this element 75 is fulcrumed at its upper end (Figure 3) upon a fulcrum pin 82 which passes transversely through the chamber 42 against one side of the element 75 and may be anchored at its opposite ends in the valve bodt 43. i

The adjuster screw 79 hasA threaded engagement at 83 in the concentric hub part 84 of the valve body 43. The outer end of the hub part 84 is recessed at 85 to receive packing 86, and a packing nut 87 is threaded upon the screw 79 to clamp and hold the packing 86 tightly in place. Mounted upon the polygonal outer end 88 of the screw 79 to turn the screw therewith is a control or selecting knob 89 having a generally conical and roughened periphery and, if desired, a supplemental knobpart 89a. The screw 79 has an integral flange 90, and adjacent this ange are a pair of friction Washers 91 between which is clamped the inwardly offset radial wall 92 of the dial 93. The `dial 93 and the washers 91, are clamped in place and against rotation with respect to the temperature selecting screw 79 by means of a screw 94. The shank of this screw 94 is threaded into the outer end of the screw 79 and its head engages in a recess in the outer end of the knob 89.

The generally conical flange 95 of the dial 93 has temperature markings 96 which are adapted to be brought selectively into register with a fixed indicator 97 by turning the knob 89 to set the thermally operated device to maintain any desired temperature. For example, by setting the dial 93 with the 400 marking in register with the indicator l97 a temperature of 400 F. will be maintained within the oven 6, and by turning the knob 89 to bring the 450 or 350 markings into register with the indicator 97 the inner end of the screw 79 will be moved inwardly or outwardly, and, by its cooperation with the adjacent end of the element 75, will set the thermally operated device to maintain a temperature of 450" F. or 350 F. within the oven. An annular mounting or bevel ring 100 is mounted in the opening 101 formed in the panel 9 and supports and positions the valvebody 43. This ring 100 has the outer part radially flanged at 102 and the inner cup-shaped part 103 telescopically engaged therewith. The indicator 97 is positioned on the radial flange 102 of the ring 100 and a coiled spring 105 is interposed between the base 106 of the part 103and a cupshaped ring 107 mounted upon the screw 79 and seating against the flange 90.

For the purpose of. always maintaining at least some supply of gas from the manifold 20 to the oven burner 28 when the valve 33 is open so that the burner 28 cannot be extinguished by the regulator with the valve 33 open, a by-pass opening 108 opens from the chamber 42 into the outletchamber around the valve 60. A metering screw 109 threaded into the valve body 43 has a tapered end for metering cooperation with a tapered seat in the by-pass opening 108 for metering the opening 108 and the by-passed fuel supply therethrough.

The general operation of the illustrated emollows:

Assuming that the valve 33 is open and the dial 89 of the selector 80 is set with the dial marking 400 at the indicator 97, as shown in Figure 2, to position the valve 60 for supplying gaseous fuel to the burner 28 in an amount to maintain a temperature of 400 F. within the' oven, the gaseous. fuel supply for the oven burner will pass from the manifold 20 through the pipe line part 29, loop 3,5, pipe line part 40, chamber 42, outlet 50 and pipe line 51, 53, 54, to the burner 28, through the mixing head 30 where the desired air is admitted. The burner 28, thus supplied with gaseous fuel when ignited, heats the oven chamber 6 which, in turn, heats the loop 35 and the gas conveyed therethrough. Since the temperature lselecting means is related to the deflection value of the thermostatic metals forming the bi-metallic element 75, it is apparent that as the temperature within the oven appreaches the pre-determined or pre-selected temperature, the gas passingthrough the loop 35 will also be heated relative thereto, and upon passing through the chamber 42 this pre-heated gas will impart direct thermal influence upon the bi-metallic element 75 to maintain a uniform temperature within the oven. If the oven temperature tends to rise above that for which the regulator is set, the temperature of the fuel passing through the loop 35 will be increased and the element 75, lying in the path of the heated fuel, will be warped rapidly in a direction to permit movement of the valve 60 toward closed position an amount to lower the oven temperature to that for which the device is set. Similarly, if the oven temperature tends to drop below that for which the device is set, the temperature of the fuel passing through the loop 35 will ybe reduced and the element 75 will be warped Y by the direct thermal influence of the preheated fuel thereon to move the valve G0 toward open position an amount which will raise the temperature of the oven to that for which the device is set. i

The particular formation of the loop or fuel pre-heating 'portion 35 of the delivery line may vary widely within the scope of the present invention. For example, in Figure 5, instead of being in the form of a simple loop as shown 100 bodiment of the invention is substantially as in Figure 2, theloop 35a has a serpentine leg 112, and in Figure 6, the heating part of the fuel delivery line is in the form of a generally conical coil 3512 having the larger inlet end 113 at the top' and the smaller outlet end 114 at the bottom. In Figure '7, the two sides 115 and 116 of the loop 35e are brought together and the return bend between these sides is in the form of a relatively small open loop portion 117.

In the embodiment of Figures 8 and 9, the loop 35d has its leg 118 flattened at 119 so that, in passing through the leg 119 of the loop, the gas will assume the form of a relatively wide shallow stream. The loops 35a, 35D, 35o and 35d, or" Figures 5 to 9 inclusive, like the loop 35 of the previous embodiment, are made of metal, preferably such as copper or aluminum, of relatively hi-"h specific heat properties for effective transfer of the heat within the oven to the stream of gas in its passage to the oven burner and anterior with respect to the thermally operated device.

In the modified form of regulator unit a"- sembly, shown in Figure 4, the outlet 120 leading from the chamber 42 within the valve body 43 leads rearwardly instead of downwardly asin the embodiment shown in Figure 3. The

fuel supply-pipe 51' is` connected to the valve cap 67 by a suitable joint 121. The cap 67' has the outlet opening 122. The outlet 50' is controlled by the valve 60 between which and the cap 67 the generally conical spring 65' is coniined. The valve 60 has the annular seat 63 which is adapted to seat upon the seat 62 around the outlet opening 50', and the valve also has an annular guide 123 which operates slidingly in the opening 50. The outer end of the outer enlarged part of the valve, Apin 124 is secured to the adjacent end of the bi-metallic element '75 which is disposed, as before, within the chamber 42 to lie directly in the path of the gaseous fuel supply through the valve body 43 to the oven burner. The enlarged outer part of the pin 124 forms a shoulder 125 which abuts the bottom of the cup-like guide 123 which is disposed between the outer side of the valve 60' and the shoulder 125, and the reduced inner Jend of the pin 124 passes axially through the bottom of the guide 123 and into an axial `recess in the valve 60. 'Y

The opposite end of the bi-metallic element 75' is riveted by a pair of laterally disposed rivets 127 to` a pivotingr lever 128 which lever has a fulcrum 129 bearing and fulcruming the adjacent'end of the element '75 upon the inner wall 130 o the valve body 43'. The outwardly offset end 132 of the lever 128 overlaps the element 75. The inner end of the temperature adjusting or selecting screw 79 has a reduced projection 134 which extends into an aperture in the oiset end 132 of the lever 128 and the lever 128 has free abutting contact with the tapered shoulder 135 on the screw '79' adjacent the reduced projection 134.- Considering the valves 60 and 69 of Figures 3 and 4 respectively as the load, and the engagement of the adjusting screws 79 and 79" with the elements 75 and 75' as thefpoints of application of the temperature adjusting or selecting force, the lever formed by the element 75 of Figure 3, and the lever formed by the element '75 and lever 128 of Figure 4. are both `of the third class.

In the embodiment of Figure'4, the adjusting screw 79' is threaded in the hub part 84' of the valve body and the outer reduced end of the hub part passes through an opening 140 in the front panel 9 and through a washer 141 disposed between the inner side of the panel and the shoulder formed on the screw 79. The bezel 142 has a flat inner wall clamped to the outer side of the panel-9' by a nut 143 which is threaded at 144 upon the screw '79' and secures` the valve body firmly in place to the panel 9 and the bezel 142 in place upon the outer side of the panel. The screw '79 has a iiange 146 and the knob 89' is non-rotatably mounted upon the outer end of the screw 79 which is splayed at 147 foi preventing rotation of the knob relative the screw. The knob 89 is secured against axial displacement by a screw 148 and secured to the inner side of the knob 89 by screws 15D is av dial locking washer 151. This washer is offset marginally at 152 and the outer radial iiange of the dial 93 is clamped between the inner side of the knob 89' and the oiset margin 152 of the washer 151. The generally conical periphery of the dial 93 has the usual or any suitable temperature markings for cooperation with an indicator as before, and the outer end of the hub 84 is recessed at 85' to receive packing 86 which is held tightly in place by a spring 154 interposed between the packing washer 155 and the flange 146. A

The inlet pipe 29 is connected by a joint 156 to one end of the elbow inlet fitting 157 and the other end of this fitting' is threaded at 158 to theinletJ 41. The by-pass passage from the chamber 42 to the outlet 120 is indicated at 160 and the burner ame maintaining screw for this passage is indicated at 161.

In the water heater embodying the invention as shown in Figure 10, the water tank is shown at 180. It may be of the type illustrated or of any other suitable or preferred type`.`\Underlying the bottom 181 of the tank 180 to heatthe water within the tank is a suitable atmospheric gas burner 182. The gas suply pipe for supplying gas to the burner 182 is shown at 183 and the heater has4 a cold water inlet pipe 184 for supplying cold-water to the tank 180 and a hot water pipe 185 for delivering hot water from the tank. I f- The gas supply pipe 183 has a pre-heating loop 186 for pre-heating the gaseous fuel supply to the burner 182. As in the preceding embodiments, the loop 186 is preferably made of metal of relatively high specific heat properties. Where it is separate from pipe sections forming the gas supply pipe 183, as shown, it may be connected into the gas supply pipe line 183 and xed in place in the tank 180 by a fitting 198. This fitting seals the opening 199 through which the loop 186 is inserted and it makes tight joints between the ends of the loop 186 and the adjacent ends of the gas'supply pipe sections.` The loop 186 is disposed within the tank 180 in direct contact with the water within the tank and preferably in such a. way and in such a place that it will be subject to the prevailing temperature of the water within the tank 180. This loop 186` is subject to the temperature of the water within the tank 180 and serves, as before, to pre-heat, anterior to the burner 182`and interior to the controlling device 187, the gaseous fuel supply to the burner.

The controlling device 187 comprises, as before, a. valve body or housing 188 having'a chamber 189 provided with a gas inlet 190 and a gas outwhich the device is set.

let 191. The gas supply Pipe 183 is connected to the inlet 190, and the outlet 191 is connected to the burner by a mixing head or other suitable arrangement for supplying the necessary air in the usual or any desired manner. As before, the fuel outlet 191, leading from the chamber 189 to the burner 182, is controlled by a valve 192. The bi-metallic element 193 is disposed within the chamber 189 to lie directly within the path of gaseous fuel from the gas supply pipe 183 through the valve body 188 to the burner 182. The upper end of the bi-metallic element cooperates with the valve 192, and near its lower end this element is fulcrumed at 194. The temperature selecting device 195 may cooperate with the bi-metallic element 193 intermediate the i ulcrum 194 and the cooperation of the element 193 with the .valve 192, as before, and the control or selecting knob 196 may be arranged on the outside of the lower supporting part of (he tank 180 for convenient access, or otherwise as desired. The details of the thermostat and teinperature selecting device may follow the details of the preceding embodiments, or may be of any equivalent form, and a description of these details will not, therefore, be repeated in connection With this embodiment of 'the invention. Suffice it to make reference to the other embodiments herein illustrated for a full understanding of a suitable device for purposes of this embodiment of the invention.

The operation of the water heater embodiment of the invention illustrated in Figure 10 is substantially the same as the operation of the other embodiments of the invention except that the gaseous fuel is pre-heated by the temperature of the water within the tank or container instead of by the temperature with'n the oven or other enclosed space. The selecting device 195 is adapted for setting the controlling arrangement to maintain any desired temperature and the valve 192 is positioned by the selecting device and according to the setting of that device for the supply of gaseous fuel to the burner 182 in an amount to maintain the selected temperature. The burner 182 thus supplied with gaseous fuel when ignited heats the Water in the tank 180 which, in turn, heats the loop 186 and the gas conveyed therethrough. If the temperat1 e of the Water in the tank 180 tends to rise above that for which the regulator is set, the temperature of the fuel passing through the loop 186 will be increased and the bi-metallic element 193 lying in the path of the heating fuel will be warped in a direction to permit movement of the valve 192 toward closed position an amount to lower the temperature of the Water within the tank 180 to that for If the temperature of the Water Within the tank 180 tends to drop below the temperature for which the device is set, the temperature of the fuel passing through the loop 186 will be reduced and the bi-metallic element 193 will be warped by the direct thermal influence of the pre-heated fuel thereon to move the'valve 192 toward open position an amount which will ra'se the temperature of the Water 2 in the tank 180 to that for which the device is set.

The invention is capable of a wide range of modification and is adapted for a wide range oi uses, and I do not intend, therefore, to be limited to the particular details nor to the particular uses shown or described.

I claim:

1. The method of heat regulation which comprises pre-heating the heating medium and automatically controlling said medium solely by the pre-heated temperature thereof and posterior to the pre-heating of said medium.

2. The method of heat regulation which oomprises delivering a heating medium to a heater, pre-heating said medium anterior to the heater and automatically controlling the supply of the heating medium to the heater solely by means of the pre-heated temperature of said medium and posterior to the pre-heating of said medium.

3. The method of regulating the temperature of an enclosed space having a burner therefor which comprises passing gaseous fuel for the burner through said space anterior to the burner, pre-heating said fuel in its passage through said space and automatically controlling the supply of fuel to the burner solely by means of the pre-heated temperature of the fuel and posterior to the pre-heating of said medium.

4. The method of regulating the temperature of an enclosed space having a heater therefor, and means for delivering a heating medium to said heater which comprises pre-heating the heating medium anterior to the heater and by means of the temperature of the space and controlling posterior .to the pre-heating of said medium the supply of heating medium to the heater by means of the pre-heated temperature of said medium.

5. The method of heat regulation which comprises thermally regulating the delivery of the heating medium, pre-heating said medium anterior to said thermal regulation and controlling said thermal regulation by the pre-heated temperature of said medium.

6. The method of regulating the temperature of an enclosed space having means for supplying gaseous fuel for heating said space, and a bi-metallic element for controlling the supply 'of gaseous fuel which comprises pre-heating the gaseous fuel by means of the temperature of the space to be heated and passing posterior to the pre-heating of said fuel the preheating fuel over and in direct contact with said bi-metallic element.

'7. In combination, a heater, means for delivering a heating mediumto said heater, means for pre-heating the heating medium, and means posterior to the preheating of the heating medium for controlling the supply of heating medium to the heater by the pre-heated temperature of said medium.

8. In combination, an enclosed space, a burner for heating said space, means for delivering fuel to said burner, means for subjecting the fuel to the thermal influence of said space to pre-heat the fuel, and means posterior to the preheating of the fuel for controlling the supply of fuel to the burner by the pre-heated temperature of the fuel.

9. In combination, a space to be heated, a burner for heating said space, means for delivering fuel to said burner, a control device for controlling said fuel delivery, means for subjecting the fuel to the thermal inuence of said space to pre-heat the fuel and a thermally operated device disposed in the path of preheated fuel posterior to the position in which the fuel is subjected to the thermal influence of said space and adapted for operating said control device.l

10. In combination, a valve body having 5150 chamber and a fuel outlet and fuel inlet for supplying fuel through said chamber, a valve for said outlet, a thermally operated device disposed Within said chamber anterior to said valve to lie in the path of the fuel supply through the chamber and adapted for operating said valve, and means for pre-heating the fuel supply anterior to said Valve body.

l1. In combination, an oven, a gas burner therefor, a delivery line for supplying fuel to said burner and having a fuel pre-heating portion disposed within the oven, a valve body connected into said line and provided with an internal chamber through which the pre-heated fuel is adapted to pass to the burner, a valve for controlling the supply of fuel through said line, and a thermally operated device disposed in said chamber to lie in the path of the pre-heated fuel supply through said chamber and adapted for operating said valve.

12. In combination, an oven, a gas burner therefor, a delivery line for supplying fuel to said burner and having a fuel pre-heating portion disposed within the oven, a valve body connected into said line and provided with an internal chamber through which the pre-heated fuel is adapted to pass to the burner, a valve for controlling the supply of fuel through said line, a thermally operated device disposed in said chamber to lie in the path of the pre-heated fuel supply through said chamber and adapted for operating said valve, and a temperature selecting device mounted on said valve body and adapted for operating said thermally operated device to adjust the setting of said valve.

13. In combination, an oven, a gas burner therefor, a gas supply manifold, a gas delivery line having a pre-heating loop disposed within the oven, a valve body connected to said line posterior to said heating loop, a gas line leading from said valve body to the burner, a valve' controlling the fuel supply to the burner, and a thermally operated device disposed within said valve body to lie in the path of the preheated fuel and adapted for operating said valve.

14. The method of regulating a water heater apparatus having means for delivering a heating medium thereto which comprises pre-heating the heating medium by means of the temperature of the water in said apparatus and controlling the supply of heating medium by means of the pre-heated temperature of said medium.

15. In combination, a Water heater comprising a water container and a burner therefor, means for delivering fuel to said burner, means for subjecting the fuel to the thermal influence of the Water in said container, and means for controlling the supply of fuel to the burner by the pre-heated temperature of the fuel.

16. The method of controlling the delivery of heating medium to a burner which comprises preheating at least a portion of the heating medium anterior to the burner and posterior to the heating of said heating medium thermally controlling the delivery of said medium to the burner by the pre-heated temperature of said medium.

17. The method of heat regulation which comprises thermally regulating the delivery of the heating medium, pre-heating said medium remote from said thermal regulation, and controlling said thermal regulation by the preheated temperature of said medium. I

, OSCAR J. LEINS. 

